Mantoloking wants to put giant sand bags in place to help protect its coastline

Mar. 25, 2013

What is a geotextile wrap?

Mantoloking wants to protect its beach and borough with something called geotextile fabric wraps, which are sometimes called geotubes, but borough officials say these wraps are bigger and stronger. The wraps can be as big as a car, are made of a synthetic fabric stuffed with sand and gravel and get buried at the core of a dune. Experts said these wraps bolster a dune, so when a wave hits, that strengthened dune serves like a speed bump to minimize the ultimate impact on what the dune protects.

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MANTOLOKING — It took a superstorm that cracked open homes, spilled debris across town and into the bay and swallowed a portion of the only highway to relaunch old conversations about beach replenishment in the borough.

But Mantoloking needs a short-term solution to the flooding it has suffered since Sandy ripped out its dunes. Beach replenishment is a long-term goal.

Officials there have an idea to use geotextile fabric wraps (picture a really big sand bag) at the core of a temporary dune to help give the borough storm protection now while it waits for what it really needs: a wider beach and permanent dune system.

The fabric wraps — that resident Chris Nelson likened to a calzone filled with sand and gravel instead of mozzarella and sauce — would cost millions less than a rock-based wall like the one approved in Bay Head. The wraps have also proved they can work, and did in Beach Haven during Sandy. Hear from Nelson and see what Mantoloking looks like now by watching the video above. Using our iPhone app? Watch the video here.

Much like with beach replenishment, Mantoloking can’t move forward without support from each of the 128 oceanfront property owners. But unlike years ago, when officials led a failed fight for boroughwide beach replenishment, the town plans to see this effort through to give it the storm protection Sandy proved it needs.

“We have to,” Nelson said. “We can’t have other people’s homes in other people’s homes. It has to happen.”

Sandy shattered Mantoloking’s homes and tossed them like toys into the Barnegat Bay. It carved three inlets to connect the ocean and bay, pulling out more homes, slicing open Route 35 and flooding towns farther west.

Significant damage despite dunes

Roughly half of the 528 homes within the borough’s 2.2-mile stretch of Ocean County’s northern barrier island were significantly damaged, said Nelson, who has acted as special counsel to the mayor and council since the storm. More than 50 oceanfront homes are completely destroyed, he said.

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The borough’s best protection against Sandy were dunes that state officials even deemed strong, Nelson said. Now the beach is flat and, despite the town’s temporary berms, the ocean has spilled onto Route 35 each of the four times a nor’­easter hit, Nelson said.

The borough’s engineer proposed geotextile fabric wraps — sometimes called geotubes, but town officials say the wraps are bigger and stronger — as the best solution to its immediate problems, Nelson said. The wraps are car-size pillowlike objects made of synthetic fabric stuffed with sand and gravel, he said.

Geotextiles give an “added hardness factor” to a dune, which is really little more than loose sand, said marine geology professor Stewart Farrell, who directs the Coastal Science Center at the Richard Stockton College of New Jersey.

If Mantoloking had them when Sandy hit, the water still would have gone through the dunes, but the added protection measure — acting like a speed bump — could have better protected the homes, he said.

“The geotextiles would be a big help. They’re not that expensive. The owners will probably be contributors, but you’ve got to get 100 percent acceptance,” Farrell said.

Nelson said the borough considered rocks like neighboring Bay Head, but with costs ranging from $30 million to $45 million, it wasn’t feasible. These wraps, used over the 2.2-mile stretch, could cost around $8 million, he said. The borough plans to budget $1 million to $2 million, hoping for state and federal funds to cover the balance, he said.

Mike Becker, a 15-year resident, questions the strength of the wraps. He thought they looked like a screen. He has his own plan, using 5,000- to 6,000-pound rocks on the beach outside his oceanfront home.

The geotextiles could tear or need to be replaced, and Sandy proved sand can be pushed any direction, Becker said.

“Six-thousand-pound rocks don’t move,” he said.

Nelson said the borough is looking at Kevlar, a high-impact material used by military, for the fabric wrap.

Farrell thinks geotextiles could help Mantoloking, but said what the borough ultimately needs is a wider beach.

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He explained a 10-foot breaking wave packs enough inertia that it can be like a Mack truck careening toward a brick wall. A wide beach would work against the wave like that truck on a runaway ramp, the soft sand-covered incline off highways where trucks can make an emergency stop, he said.

“The wave is like a runaway truck, and you have to stop it,” Farrell said. “If you have 300 feet, 250 feet between the final break-point of the wave and where it runs into something solid like the dunes or the houses, it isn’t so bad. If it’s 30, 40 feet, it’s a lot worse.”

Sandy took over Mantoloking’s beach, now less than 100 feet at its widest point, within the first two hours, Farrell said. That left only the borough’s dune between the surges and homes by the second high tide.

Quick installation touted by town

If the town meets its goal, the wraps could be in place by hurricane season while beach replenishment, its long-term goal, could be years away, Nelson said.

But even the quicker solution resurfaces an old problem in Mantoloking.

The beaches along Mantoloking are privately owned, which means the borough needs easements from each oceanfront homeowner or beach association to give the Army Corps of Engineers permission to pump sand onto the private beaches.

Mayor George Nebel and the council members pushed for federally funded beach replenishment for a number of years, but never secured enough easements before the effort stalled. Had they succeeded, Mantoloking could have been in line for a 350-foot wide beach with 22-foot-high dunes, Nelson said.

To Nebel, the need is even more obvious now.

“Look at the town,” he said. “We don’t want it to happen again. I don’t think anybody will reconstruct anything if we don’t protect our town better than we had before.”

After Sandy, the borough officials had located the displaced residents, but received 122 verbal agreements from oceanfront homeowners, Nelson said. However, the town needs signed easements in hand and must start the process over because the geotextile wraps were not included in the original easement, he said.

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There still are some holdouts, but efforts are under way to change their minds, Nelson said.

“We hope people will see this enhancement and this improvement and be willing to participate,” Nelson said. “We’re going to move forward regardless. We can’t stop. It’s going to be done.”

Mantoloking officials don’t have to look far to see if the geotextiles can work, Farrell said; they have been used in Avalon, Atlantic City, Ocean City and Sea Isle City. Sea Isle City, in Cape May County, has the largest current installation, at 2,000 feet long, he said.

A section of beach along the ocean side of Beach Haven, less than 500 feet between Merivale and Nelson avenues, has geotubes that did their job against Sandy, said Richard Crane, Beach Haven’s borough manager.

“It has worked wonderfully for us certainly during Sandy and even before Sandy on the most vulnerable portion of the beachfront in town,” he said.

The 2010 project cost roughly $500,000, though the borough paid about 25 percent with the state’s support, Crane said.